2022-10-03 23:11:49

by Lad, Prabhakar

[permalink] [raw]
Subject: [RFC PATCH v2 0/2] AX45MP: Add support to non-coherent DMA

From: Lad Prabhakar <[email protected]>

Hi All,

On the Andes AX45MP core, cache coherency is a specification option so it
may not be supported. In this case DMA will fail. To get around with this
issue this patch series does the below:

1] Andes AX45MP core has a Programmable Physical Memory Attributes (PMA)
block that allows dynamic adjustment of memory attributes in the runtime.
It contains a configurable amount of PMA entries implemented as CSR
registers to control the attributes of memory locations in interest. PMA
regions are passed from the l2 node which are configured as
non-cacheable and bufferable with the SBI call.

l2cache: cache-controller@13400000 {
....
pma-regions = <0x0 0x00000000 0x0 0x14000000>,
<0x0 0x20000000 0x0 0x10000000>,
<0x0 0x58000000 0x0 0x08000000>;
....
};

2] We provide callbacks to synchronize specific content between memory and
cache.

- arch_sync_dma_for_device()
- arch_sync_dma_for_cpu()

Below are the configs that are enabled:

- DMA_GLOBAL_POOL
- RISCV_DMA_NONCOHERENT

Below is the L2 cache DT node:

l2cache: cache-controller@13400000 {
compatible = "andestech,ax45mp-cache", "cache";
cache-size = <0x40000>;
cache-line-size = <64>;
cache-sets = <1024>;
cache-unified;
reg = <0x0 0x13400000 0x0 0x100000>;
pma-regions = <0x0 0x00000000 0x0 0x10000000>,
<0x0 0x10000000 0x0 0x04000000>,
<0x0 0x20000000 0x0 0x10000000>,
<0x0 0x58000000 0x0 0x08000000>;
interrupts = <SOC_PERIPHERAL_IRQ(476, IRQ_TYPE_LEVEL_HIGH)>;
};

Due to the above approach custom SBI calls have been implemented. The
above implementation is in preparation for adding support for Renesas
RZ/Five SoC which uses the AX45MP core. As with the above approach the
kernel image might not be generic so that it can be used on other
platforms, so sending it as an RFC (without DT binding patches).

OpenSBI implementation isn't upstreamed yet, public repo for access is
available at [0].

[0] https://github.com/renesas-rz/rz_opensbi/tree/work/OpenSBI-PMA

RFC v1-> RFC v2
* Moved out the code from arc/riscv to drivers/soc/renesas
* Now handling the PMA setup as part of the L2 cache
* Now making use of dma-noncoherent.c instead SoC specific implementation.
* Dropped arch_dma_alloc() and arch_dma_free()
* Switched to RISCV_DMA_NONCOHERENT
* Included DT binding doc

RFC v1: https://patchwork.kernel.org/project/linux-renesas-soc/cover/[email protected]/

Sending this as an RFC as CONFIG_ERRATA_THEAD_CMO/CONFIG_ARCH_R9A07G043
is used for determining the CMO to call it would better if we could do
this runtime instead.

Cheers,
Prabhakar

Lad Prabhakar (2):
dt-bindings: soc: renesas: r9a07g043f-l2-cache: Add DT binding
documentation for L2 cache controller
soc: renesas: Add L2 cache management for RZ/Five SoC

.../soc/renesas/r9a07g043f-l2-cache.yaml | 82 ++++
arch/riscv/include/asm/cacheflush.h | 8 +
arch/riscv/include/asm/errata_list.h | 2 +
arch/riscv/include/asm/sbi.h | 1 +
arch/riscv/mm/dma-noncoherent.c | 20 +
drivers/soc/renesas/Makefile | 4 +
drivers/soc/renesas/rzf/Makefile | 3 +
drivers/soc/renesas/rzf/ax45mp_cache.c | 365 ++++++++++++++++++
drivers/soc/renesas/rzf/rzf_sbi.h | 27 ++
9 files changed, 512 insertions(+)
create mode 100644 Documentation/devicetree/bindings/soc/renesas/r9a07g043f-l2-cache.yaml
create mode 100644 drivers/soc/renesas/rzf/Makefile
create mode 100644 drivers/soc/renesas/rzf/ax45mp_cache.c
create mode 100644 drivers/soc/renesas/rzf/rzf_sbi.h

--
2.25.1


2022-10-03 23:26:57

by Lad, Prabhakar

[permalink] [raw]
Subject: [RFC PATCH v2 1/2] dt-bindings: soc: renesas: r9a07g043f-l2-cache: Add DT binding documentation for L2 cache controller

From: Lad Prabhakar <[email protected]>

Add DT binding documentation for L2 cache controller found on RZ/Five SoC.

The Renesas RZ/Five microprocessor includes a RISC-V CPU Core (AX45MP
Single) from Andes. The AX45MP core has an L2 cache controller, this patch
describes the L2 cache block.

Signed-off-by: Lad Prabhakar <[email protected]>
---
.../soc/renesas/r9a07g043f-l2-cache.yaml | 82 +++++++++++++++++++
1 file changed, 82 insertions(+)
create mode 100644 Documentation/devicetree/bindings/soc/renesas/r9a07g043f-l2-cache.yaml

diff --git a/Documentation/devicetree/bindings/soc/renesas/r9a07g043f-l2-cache.yaml b/Documentation/devicetree/bindings/soc/renesas/r9a07g043f-l2-cache.yaml
new file mode 100644
index 000000000000..f96eeffa58ce
--- /dev/null
+++ b/Documentation/devicetree/bindings/soc/renesas/r9a07g043f-l2-cache.yaml
@@ -0,0 +1,82 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+# Copyright (C) 2022 Renesas Electronics Corp.
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/soc/renesas/r9a07g043f-l2-cache.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: SiFive L2 Cache Controller
+
+maintainers:
+ - Lad Prabhakar <[email protected]>
+
+description:
+ A level-2 cache (L2C) is used to improve the system performance by providing
+ a larger amount of cache line entries and reasonable access delays. The L2C
+ is shared between cores, and a non-inclusive non-exclusive policy is used.
+
+properties:
+ compatible:
+ items:
+ - const: andestech,ax45mp-cache
+ - const: cache
+
+ reg:
+ maxItems: 1
+
+ interrupts:
+ maxItems: 1
+
+ cache-line-size:
+ const: 64
+
+ cache-level:
+ const: 2
+
+ cache-sets:
+ const: 1024
+
+ cache-size:
+ enum: [131072, 262144, 524288, 1048576, 2097152]
+
+ cache-unified: true
+
+ next-level-cache: true
+
+ pma-regions:
+ $ref: /schemas/types.yaml#/definitions/uint32-matrix
+ minItems: 1
+ maxItems: 16
+ description: Optional array of memory regions to be set as non-cacheable
+ bufferable regions which will be setup in the PMA.
+
+additionalProperties: false
+
+required:
+ - compatible
+ - cache-line-size
+ - cache-level
+ - cache-sets
+ - cache-size
+ - cache-unified
+ - interrupts
+ - reg
+
+examples:
+ - |
+ #include <dt-bindings/interrupt-controller/irq.h>
+
+ cache-controller@2010000 {
+ reg = <0x13400000 0x100000>;
+ compatible = "andestech,ax45mp-cache", "cache";
+ interrupts = <508 IRQ_TYPE_LEVEL_HIGH>;
+ cache-line-size = <64>;
+ cache-level = <2>;
+ cache-sets = <1024>;
+ cache-size = <262144>;
+ cache-unified;
+ pma-regions = <0x00000000 0x10000000>,
+ <0x10000000 0x04000000>,
+ <0x20000000 0x10000000>,
+ <0x58000000 0x08000000>;
+ };
--
2.25.1

2022-10-04 07:38:00

by Geert Uytterhoeven

[permalink] [raw]
Subject: Re: [RFC PATCH v2 1/2] dt-bindings: soc: renesas: r9a07g043f-l2-cache: Add DT binding documentation for L2 cache controller

Hi Prabhakar,

On Tue, Oct 4, 2022 at 12:32 AM Prabhakar <[email protected]> wrote:
> From: Lad Prabhakar <[email protected]>
>
> Add DT binding documentation for L2 cache controller found on RZ/Five SoC.
>
> The Renesas RZ/Five microprocessor includes a RISC-V CPU Core (AX45MP
> Single) from Andes. The AX45MP core has an L2 cache controller, this patch
> describes the L2 cache block.
>
> Signed-off-by: Lad Prabhakar <[email protected]>

Thanks for your patch!

> --- /dev/null
> +++ b/Documentation/devicetree/bindings/soc/renesas/r9a07g043f-l2-cache.yaml

Not andestech,ax45mp-cache.yaml?

> @@ -0,0 +1,82 @@
> +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
> +# Copyright (C) 2022 Renesas Electronics Corp.
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/soc/renesas/r9a07g043f-l2-cache.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: SiFive L2 Cache Controller

Andestech AX45MP?

> +
> +maintainers:
> + - Lad Prabhakar <[email protected]>
> +
> +description:
> + A level-2 cache (L2C) is used to improve the system performance by providing
> + a larger amount of cache line entries and reasonable access delays. The L2C
> + is shared between cores, and a non-inclusive non-exclusive policy is used.
> +
> +properties:
> + compatible:
> + items:
> + - const: andestech,ax45mp-cache
> + - const: cache

This makes the schema apply to any node which is compatible with
"cache", cfr. the report from Rob's bot.

You need a select block to avoid that, cfr.
Documentation/devicetree/bindings/riscv/sifive-l2-cache.yaml.

Gr{oetje,eeting}s,

Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- [email protected]

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds

2022-10-04 07:57:01

by Lad, Prabhakar

[permalink] [raw]
Subject: Re: [RFC PATCH v2 1/2] dt-bindings: soc: renesas: r9a07g043f-l2-cache: Add DT binding documentation for L2 cache controller

Hi Geert,

Thank you for the review.

On Tue, Oct 4, 2022 at 7:42 AM Geert Uytterhoeven <[email protected]> wrote:
>
> Hi Prabhakar,
>
> On Tue, Oct 4, 2022 at 12:32 AM Prabhakar <[email protected]> wrote:
> > From: Lad Prabhakar <[email protected]>
> >
> > Add DT binding documentation for L2 cache controller found on RZ/Five SoC.
> >
> > The Renesas RZ/Five microprocessor includes a RISC-V CPU Core (AX45MP
> > Single) from Andes. The AX45MP core has an L2 cache controller, this patch
> > describes the L2 cache block.
> >
> > Signed-off-by: Lad Prabhakar <[email protected]>
>
> Thanks for your patch!
>
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/soc/renesas/r9a07g043f-l2-cache.yaml
>
> Not andestech,ax45mp-cache.yaml?
>
I wasn't sure as we were including this in soc/renesas so named it as
r9a07g043f-l2-cache.yaml if there are no issues I'll rename it
andestech,ax45mp-cache.yaml.

> > @@ -0,0 +1,82 @@
> > +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
> > +# Copyright (C) 2022 Renesas Electronics Corp.
> > +%YAML 1.2
> > +---
> > +$id: http://devicetree.org/schemas/soc/renesas/r9a07g043f-l2-cache.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: SiFive L2 Cache Controller
>
> Andestech AX45MP?
>
Ouch!

> > +
> > +maintainers:
> > + - Lad Prabhakar <[email protected]>
> > +
> > +description:
> > + A level-2 cache (L2C) is used to improve the system performance by providing
> > + a larger amount of cache line entries and reasonable access delays. The L2C
> > + is shared between cores, and a non-inclusive non-exclusive policy is used.
> > +
> > +properties:
> > + compatible:
> > + items:
> > + - const: andestech,ax45mp-cache
> > + - const: cache
>
> This makes the schema apply to any node which is compatible with
> "cache", cfr. the report from Rob's bot.
>
Actually dt_binding_check didn't complain when I ran it locally (maybe
it's time to update dt-schema).

> You need a select block to avoid that, cfr.
> Documentation/devicetree/bindings/riscv/sifive-l2-cache.yaml.
>
Thanks for the pointer.

Cheers,
Prabhakar

2022-10-04 08:02:33

by Conor Dooley

[permalink] [raw]
Subject: Re: [RFC PATCH v2 1/2] dt-bindings: soc: renesas: r9a07g043f-l2-cache: Add DT binding documentation for L2 cache controller

On Tue, Oct 04, 2022 at 08:26:01AM +0100, Lad, Prabhakar wrote:
> Hi Geert,
>
> Thank you for the review.
>
> On Tue, Oct 4, 2022 at 7:42 AM Geert Uytterhoeven <[email protected]> wrote:
> >
> > Hi Prabhakar,
> >
> > On Tue, Oct 4, 2022 at 12:32 AM Prabhakar <[email protected]> wrote:
> > > From: Lad Prabhakar <[email protected]>
> > >
> > > Add DT binding documentation for L2 cache controller found on RZ/Five SoC.
> > >
> > > The Renesas RZ/Five microprocessor includes a RISC-V CPU Core (AX45MP
> > > Single) from Andes. The AX45MP core has an L2 cache controller, this patch
> > > describes the L2 cache block.
> > >
> > > Signed-off-by: Lad Prabhakar <[email protected]>
> >
> > Thanks for your patch!
> >
> > > --- /dev/null
> > > +++ b/Documentation/devicetree/bindings/soc/renesas/r9a07g043f-l2-cache.yaml
> >
> > Not andestech,ax45mp-cache.yaml?
> >
> I wasn't sure as we were including this in soc/renesas so named it as
> r9a07g043f-l2-cache.yaml if there are no issues I'll rename it
> andestech,ax45mp-cache.yaml.

I may be guilty of suggesting soc/renesas in the first place, but should
this maybe be in soc/andestech? I have no skin in the game, so at the
end of the day it doesnt matter to me, but I would imagine that you're
not going to be the only users of this l2 cache? Or is it a case of "we
will deal with future users when said future users arrive"? But either
way, naming it after the less specific compatible makes more sense to
me.

Thanks,
Conor.



2022-10-04 08:32:07

by Conor Dooley

[permalink] [raw]
Subject: Re: [RFC PATCH v2 1/2] dt-bindings: soc: renesas: r9a07g043f-l2-cache: Add DT binding documentation for L2 cache controller

On Mon, Oct 03, 2022 at 11:32:21PM +0100, Prabhakar wrote:
> From: Lad Prabhakar <[email protected]>
>
> Add DT binding documentation for L2 cache controller found on RZ/Five SoC.
>
> The Renesas RZ/Five microprocessor includes a RISC-V CPU Core (AX45MP
> Single) from Andes. The AX45MP core has an L2 cache controller, this patch
> describes the L2 cache block.
>
> Signed-off-by: Lad Prabhakar <[email protected]>
> ---
> .../soc/renesas/r9a07g043f-l2-cache.yaml | 82 +++++++++++++++++++
> 1 file changed, 82 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/soc/renesas/r9a07g043f-l2-cache.yaml
>
> diff --git a/Documentation/devicetree/bindings/soc/renesas/r9a07g043f-l2-cache.yaml b/Documentation/devicetree/bindings/soc/renesas/r9a07g043f-l2-cache.yaml
> new file mode 100644
> index 000000000000..f96eeffa58ce
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/soc/renesas/r9a07g043f-l2-cache.yaml
> @@ -0,0 +1,82 @@
> +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
> +# Copyright (C) 2022 Renesas Electronics Corp.
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/soc/renesas/r9a07g043f-l2-cache.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: SiFive L2 Cache Controller
> +
> +maintainers:
> + - Lad Prabhakar <[email protected]>
> +
> +description:
> + A level-2 cache (L2C) is used to improve the system performance by providing
> + a larger amount of cache line entries and reasonable access delays. The L2C
> + is shared between cores, and a non-inclusive non-exclusive policy is used.
> +
> +properties:
> + compatible:
> + items:
> + - const: andestech,ax45mp-cache
> + - const: cache

I think preemptively adding a "renesas,r9a07g043f-l2-cache" here is a
good idea, just in case something crops up down the line.

Thanks,
Conor.

> +
> + reg:
> + maxItems: 1
> +
> + interrupts:
> + maxItems: 1
> +
> + cache-line-size:
> + const: 64
> +
> + cache-level:
> + const: 2
> +
> + cache-sets:
> + const: 1024
> +
> + cache-size:
> + enum: [131072, 262144, 524288, 1048576, 2097152]
> +
> + cache-unified: true
> +
> + next-level-cache: true
> +
> + pma-regions:
> + $ref: /schemas/types.yaml#/definitions/uint32-matrix
> + minItems: 1
> + maxItems: 16
> + description: Optional array of memory regions to be set as non-cacheable
> + bufferable regions which will be setup in the PMA.
> +
> +additionalProperties: false
> +
> +required:
> + - compatible
> + - cache-line-size
> + - cache-level
> + - cache-sets
> + - cache-size
> + - cache-unified
> + - interrupts
> + - reg
> +
> +examples:
> + - |
> + #include <dt-bindings/interrupt-controller/irq.h>
> +
> + cache-controller@2010000 {
> + reg = <0x13400000 0x100000>;
> + compatible = "andestech,ax45mp-cache", "cache";
> + interrupts = <508 IRQ_TYPE_LEVEL_HIGH>;
> + cache-line-size = <64>;
> + cache-level = <2>;
> + cache-sets = <1024>;
> + cache-size = <262144>;
> + cache-unified;
> + pma-regions = <0x00000000 0x10000000>,
> + <0x10000000 0x04000000>,
> + <0x20000000 0x10000000>,
> + <0x58000000 0x08000000>;
> + };
> --
> 2.25.1
>

2022-10-04 09:03:51

by Lad, Prabhakar

[permalink] [raw]
Subject: Re: [RFC PATCH v2 1/2] dt-bindings: soc: renesas: r9a07g043f-l2-cache: Add DT binding documentation for L2 cache controller

On Tue, Oct 4, 2022 at 8:32 AM Conor Dooley <[email protected]> wrote:
>
> On Tue, Oct 04, 2022 at 08:26:01AM +0100, Lad, Prabhakar wrote:
> > Hi Geert,
> >
> > Thank you for the review.
> >
> > On Tue, Oct 4, 2022 at 7:42 AM Geert Uytterhoeven <[email protected]> wrote:
> > >
> > > Hi Prabhakar,
> > >
> > > On Tue, Oct 4, 2022 at 12:32 AM Prabhakar <[email protected]> wrote:
> > > > From: Lad Prabhakar <[email protected]>
> > > >
> > > > Add DT binding documentation for L2 cache controller found on RZ/Five SoC.
> > > >
> > > > The Renesas RZ/Five microprocessor includes a RISC-V CPU Core (AX45MP
> > > > Single) from Andes. The AX45MP core has an L2 cache controller, this patch
> > > > describes the L2 cache block.
> > > >
> > > > Signed-off-by: Lad Prabhakar <[email protected]>
> > >
> > > Thanks for your patch!
> > >
> > > > --- /dev/null
> > > > +++ b/Documentation/devicetree/bindings/soc/renesas/r9a07g043f-l2-cache.yaml
> > >
> > > Not andestech,ax45mp-cache.yaml?
> > >
> > I wasn't sure as we were including this in soc/renesas so named it as
> > r9a07g043f-l2-cache.yaml if there are no issues I'll rename it
> > andestech,ax45mp-cache.yaml.
>
> I may be guilty of suggesting soc/renesas in the first place, but should
> this maybe be in soc/andestech? I have no skin in the game, so at the
> end of the day it doesnt matter to me, but I would imagine that you're
> not going to be the only users of this l2 cache? Or is it a case of "we
> will deal with future users when said future users arrive"? But either
> way, naming it after the less specific compatible makes more sense to
> me.
>
As there aren't any Andestech SoCs upstream, I am in favour of keeping
in soc/renesas for maintenance. If in future there comes a new soc
from Andestech (which will go into soc/andestech) we will have to
split the maintenance work.
But anyway if there will be any users of L2 cache we could always
provide a config option which can be used by other SoCs.

Said that I'll let Geert decide on this.

Cheers,
Prabhakar

2022-10-04 09:48:02

by Lad, Prabhakar

[permalink] [raw]
Subject: Re: [RFC PATCH v2 1/2] dt-bindings: soc: renesas: r9a07g043f-l2-cache: Add DT binding documentation for L2 cache controller

HI Geert,

On Tue, Oct 4, 2022 at 10:12 AM Geert Uytterhoeven <[email protected]> wrote:
>
> Hi Prabhakar,
>
> On Tue, Oct 4, 2022 at 9:59 AM Lad, Prabhakar
> <[email protected]> wrote:
> > On Tue, Oct 4, 2022 at 8:32 AM Conor Dooley <[email protected]> wrote:
> > > On Tue, Oct 04, 2022 at 08:26:01AM +0100, Lad, Prabhakar wrote:
> > > > On Tue, Oct 4, 2022 at 7:42 AM Geert Uytterhoeven <[email protected]> wrote:
> > > > > On Tue, Oct 4, 2022 at 12:32 AM Prabhakar <[email protected]> wrote:
> > > > > > From: Lad Prabhakar <[email protected]>
> > > > > >
> > > > > > Add DT binding documentation for L2 cache controller found on RZ/Five SoC.
> > > > > >
> > > > > > The Renesas RZ/Five microprocessor includes a RISC-V CPU Core (AX45MP
> > > > > > Single) from Andes. The AX45MP core has an L2 cache controller, this patch
> > > > > > describes the L2 cache block.
> > > > > >
> > > > > > Signed-off-by: Lad Prabhakar <[email protected]>
> > > > >
> > > > > Thanks for your patch!
> > > > >
> > > > > > --- /dev/null
> > > > > > +++ b/Documentation/devicetree/bindings/soc/renesas/r9a07g043f-l2-cache.yaml
> > > > >
> > > > > Not andestech,ax45mp-cache.yaml?
> > > > >
> > > > I wasn't sure as we were including this in soc/renesas so named it as
> > > > r9a07g043f-l2-cache.yaml if there are no issues I'll rename it
> > > > andestech,ax45mp-cache.yaml.
> > >
> > > I may be guilty of suggesting soc/renesas in the first place, but should
> > > this maybe be in soc/andestech? I have no skin in the game, so at the
> > > end of the day it doesnt matter to me, but I would imagine that you're
> > > not going to be the only users of this l2 cache? Or is it a case of "we
> > > will deal with future users when said future users arrive"? But either
> > > way, naming it after the less specific compatible makes more sense to
> > > me.
> > >
> > As there aren't any Andestech SoCs upstream, I am in favour of keeping
> > in soc/renesas for maintenance. If in future there comes a new soc
> > from Andestech (which will go into soc/andestech) we will have to
> > split the maintenance work.
> > But anyway if there will be any users of L2 cache we could always
> > provide a config option which can be used by other SoCs.
>
> What about Documentation/devicetree/bindings/cache/?
>
Sounds good to me.

Cheers,
Prabhakar

2022-10-04 09:52:17

by Geert Uytterhoeven

[permalink] [raw]
Subject: Re: [RFC PATCH v2 1/2] dt-bindings: soc: renesas: r9a07g043f-l2-cache: Add DT binding documentation for L2 cache controller

Hi Prabhakar,

On Tue, Oct 4, 2022 at 9:59 AM Lad, Prabhakar
<[email protected]> wrote:
> On Tue, Oct 4, 2022 at 8:32 AM Conor Dooley <[email protected]> wrote:
> > On Tue, Oct 04, 2022 at 08:26:01AM +0100, Lad, Prabhakar wrote:
> > > On Tue, Oct 4, 2022 at 7:42 AM Geert Uytterhoeven <[email protected]> wrote:
> > > > On Tue, Oct 4, 2022 at 12:32 AM Prabhakar <[email protected]> wrote:
> > > > > From: Lad Prabhakar <[email protected]>
> > > > >
> > > > > Add DT binding documentation for L2 cache controller found on RZ/Five SoC.
> > > > >
> > > > > The Renesas RZ/Five microprocessor includes a RISC-V CPU Core (AX45MP
> > > > > Single) from Andes. The AX45MP core has an L2 cache controller, this patch
> > > > > describes the L2 cache block.
> > > > >
> > > > > Signed-off-by: Lad Prabhakar <[email protected]>
> > > >
> > > > Thanks for your patch!
> > > >
> > > > > --- /dev/null
> > > > > +++ b/Documentation/devicetree/bindings/soc/renesas/r9a07g043f-l2-cache.yaml
> > > >
> > > > Not andestech,ax45mp-cache.yaml?
> > > >
> > > I wasn't sure as we were including this in soc/renesas so named it as
> > > r9a07g043f-l2-cache.yaml if there are no issues I'll rename it
> > > andestech,ax45mp-cache.yaml.
> >
> > I may be guilty of suggesting soc/renesas in the first place, but should
> > this maybe be in soc/andestech? I have no skin in the game, so at the
> > end of the day it doesnt matter to me, but I would imagine that you're
> > not going to be the only users of this l2 cache? Or is it a case of "we
> > will deal with future users when said future users arrive"? But either
> > way, naming it after the less specific compatible makes more sense to
> > me.
> >
> As there aren't any Andestech SoCs upstream, I am in favour of keeping
> in soc/renesas for maintenance. If in future there comes a new soc
> from Andestech (which will go into soc/andestech) we will have to
> split the maintenance work.
> But anyway if there will be any users of L2 cache we could always
> provide a config option which can be used by other SoCs.

What about Documentation/devicetree/bindings/cache/?

Gr{oetje,eeting}s,

Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- [email protected]

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds